(CNN)A Walt Disney World security guard and janitor at SeaWorld's Discovery Cove were among 18 men arrested in a sex sting dubbed "Operation April's Fools," Polk County, Florida, Sheriff Grady Judd said Tuesday.

Those arrested responded to online ads from undercover detectives posing as children or custodians of children.

"Child predators are dangerous and out of control. They prowl the internet for your children -- children as young as 10 years old -- to teach them how to have sex," Judd said. "They arrive with candy and condoms and they leave in handcuffs and a one-way ride to the Polk County Jail."

A 2014 CNN investigation found that 35 Disney employees as well as two SeaWorld and five Universal employees had been arrested since 2006 for sex crimes involving children, trying to meet a minor for sex or for possession of child pornography. The parks all said at the time they have a zero tolerance policy for such behavior and require all employees to undergo extensive background checks.

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All the alleged crimes occurred outside the theme parks, except for two cases involving possession of child pornography on Disney property. None of the cases involved children or teenagers visiting the parks.

"Despite our many child predator stings and CNN national investigative reports, there are two theme park employees -- one of which was a security guard and a volunteer football coach at a Christian school, who were among the 18 caught in our most recent sting," Judd said.

The arrests announced Tuesday include Jeffrey Erich Binder, 26, of Winter Garden, Florida, who works as a security guard at Walt Disney World. A Polk County Sheriff's news release said he "arrived at the undercover location to have sexual intercourse with who he believed was a 14-year-old girl."

"While chatting online and texting, Binder told the undercover detective he wanted to do 'everything' sexual with her. He purchased and brought condoms to the undercover location," the news release said. He had his Disney security guard uniform in his car when he was arrested, according to the sheriff's office.

Binder was charged with attempted lewd battery, traveling to meet a minor, use of a computer to seduce a child and use of a two-way communication device to commit a felony. His criminal history include one previous misdemeanor arrest for "battery- domestic violence," according to the news release.

Disney World spokesperson Jacquee Wahler said Binder "has been placed on unpaid leave pending the outcome of the charges" and did not address a question about his prior arrest.

Court records show he was granted a pretrial release. A plea has not yet been entered.

Nelson showed up at the undercover location to have sex with who he thought was a 14-year-old girl, the news release said.

"He sent her pictures of his genitals, and he bought condoms on the way to the undercover location," the release said. "After his arrest, Nelson told detectives he knew the girl was 14 years old, he stopped at WalMart to buy condoms, he chatted with underage girls but this was the first time he has 'done something like this' and he was 'high' and 'horny' and thought it seemed like a good idea," the release said.

Nelson was charged with use of a two-way communication device to commit a felony, use of a computer to seduce a child, traveling to meet a minor, attempted lewd battery, transmission of harmful materials to a minor and possession of paraphernalia.

Court records show he was granted a pretrial release and a plea has not been entered.

Becca Bides, SeaWorld corporate communications director, said, "There is no greater responsibility than protecting the safety of our guests and ambassadors, and we have extensive measures in place including pre-employment criminal background checks and ongoing proactive security measures within our parks. We have zero tolerance for potential safety threats and have taken swift and appropriate action in this case."

Bides told CNN later on Tuesday that Nelson has been fired.

Others arrested in the sting include a hospital technician, computer program director, car dealership manager, airline customer service manager and a former Polk County firefighter.

As of Tuesday afternoon, only one of the suspects had entered a plea. Michael Fernandez pleaded not guilty, according to the Polk County Clerk of Courts website.